|
|
||||||||
Departments of 1 Kinesiology and 2 Physics, University of Waterloo, Waterloo N2L 3G1; and 3 Department of Surgery, University of Toronto, Toronto, Ontario, Canada M5S 1A1
In this study, we employed an in vivo model of
prolonged ischemia in rat skeletal muscle to investigate the
hypothesis that structural modifications to the sarcoplasmic reticulum
(SR) Ca2+-ATPase can explain the alterations in
Ca2+-ATPase activity that occur with ischemia. To
induce total ischemia, a tourniquet was placed around the upper
hindlimb in 27 female Sprague-Dawley rats weighing 256 ± 6.7 g (mean ± SE) and was inflated to 350 mmHg for 4 h. The
contralateral limb served as control (C) to the ischemic limb
(I), and the limbs of animals killed immediately after anesthetization
served as a double control (CC). Mixed gastrocnemius and tibialis
anterior muscles were sampled and used for SR vesicle preparation.
Maximal Ca2+-ATPase activity (µmol · g
protein
1 · min
1) of C (15,802 ± 1,246) and I (11,609 ± 1,029) was 90 and 73% (P < 0.05) of CC (17,562 ± 1,682), respectively.
No differences were found between groups in either the Hill coefficient
or the free Ca2+ at half-maximal activity. The fluorescent
probes, FITC and
N-cyclohexyl-N'-(dimethylamino-
-naphthyl) carbodiimide, used to assess structural alterations in the
regions of the ATP binding site and the Ca2+ binding sites
of the Ca2+-ATPase, respectively, indicated a 26%
reduction (P < 0.05) in FITC binding capacity
(absolute units) in I (0.22 ± 0.01) compared with CC (0.29 ± 0.02) and C (0.29 ± 0.03). Our results suggest that the
reduction in maximal SR Ca2+-ATPase activity in SR vesicles
with ischemia is related to structural modification in the
region of the nucleotide binding domain by mechanisms that are as yet unclear.
muscle; sarcoplasmic reticulum
This article has been cited by other articles:
![]() |
S. Matsunaga, T. Mishima, T. Yamada, S. Inashima, and M. Wada Alterations in in vitro function and protein oxidation of rat sarcoplasmic reticulum Ca2+-ATPase during recovery from high-intensity exercise Exp Physiol, March 1, 2008; 93(3): 426 - 433. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. R. Tupling, C. Vigna, R. J. Ford, S. C. Tsuchiya, D. A. Graham, S. G. Denniss, and J. W. E. Rush Effects of buthionine sulfoximine treatment on diaphragm contractility and SR Ca2+ pump function in rats J Appl Physiol, December 1, 2007; 103(6): 1921 - 1928. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. R. Solis, D. P. Hallihan, R. R. E. Uwiera, R. B. Thompson, E. D. Pehowich, and V. K. Mushahwar Prevention of pressure-induced deep tissue injury using intermittent electrical stimulation J Appl Physiol, May 1, 2007; 102(5): 1992 - 2001. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. W.R. Dudley, G. Danialou, K. Govindaraju, L. Lands, D. E. Eidelman, and B. J. Petrof Sarcolemmal Damage in Dystrophin Deficiency Is Modulated by Synergistic Interactions between Mechanical and Oxidative/Nitrosative Stresses Am. J. Pathol., April 1, 2006; 168(4): 1276 - 1287. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. P. Holloway, H. J. Green, and A. R. Tupling Differential effects of repetitive activity on sarcoplasmic reticulum responses in rat muscles of different oxidative potential Am J Physiol Regulatory Integrative Comp Physiol, February 1, 2006; 290(2): R393 - R404. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. D. Schertzer, D. R. Plant, J. G. Ryall, F. Beitzel, N. Stupka, and G. S. Lynch {beta}2-Agonist administration increases sarcoplasmic reticulum Ca2+-ATPase activity in aged rat skeletal muscle Am J Physiol Endocrinol Metab, March 1, 2005; 288(3): E526 - E533. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. A. Duhamel, H. J. Green, S. D. Sandiford, J. G. Perco, and J. Ouyang Effects of progressive exercise and hypoxia on human muscle sarcoplasmic reticulum function J Appl Physiol, July 1, 2004; 97(1): 188 - 196. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |